Collapsible material handling and storage container

ABSTRACT

A collapsible container which, in its uncollapsed state, is a substantially rectilinear box having a height H, a width W, and a length L. The sidewalls of the container are formed by the hinged combination of six rectangular, rigid sidewall panels. The floor structure of the container is made up of two trapezoidal panels, each having a long base edge of length L and a short base edge of length (L - W), and four right-triangular panels having two edges of equal length W/2. A two-way mechanical drive is connected between the opposing pairs of end-wall panels to collapse or erect the container in a single operation. The two larger sidewall panels are unaffected during the collapsing and erecting operation, allowing access doors to be placed therein as desired. Wheels mounted at the lower four corners of the container are operable when the container is either collapsed or erected. A center bar positioned under the floor panels provides a guide for carriages which are screw-driven from a rotary power source, and further acts as a floor support joist. The center bar supports the floor panels in a co-planar, toggle-locked position. Ramp flanges extending downwardly from the floor panels engage with a moving carriage to break the toggle-lock by lifting the floor at the beginning of the collapsing operation.

United States Patent 1191 Coleman COLLAPSIBLE MATERIAL HANDLING ANDSTORAGE CONTAINER [76] lnventor: Kenneth L. Coleman, 1825 N.

' Lincoln Plaza, Apt. 105, Chicago,

Ill. 60614 22 Filed: Dec. 3,1973

21 Appl. No.: 421,238

[52] US. Cl. 220/6, 220/1.5 [51] Int. Cl 865d 7/24 [58] Field of Search220/6, 7, 75, 1.5

[56] References Cited UNITED STATES PATENTS 2,803,084 8/1957 Freslting220/6 X 3,602,388 8/1971 l-lurkamp 220/6 X PrimaryExaminer-William 1.Price Assistant Examiner-Steven M. Pollard Attorney, Agent, orFirnt--Molinare, Allegretti, Newitt & Witcoff {57] ABSTRACT Acollapsible container which, in its uncollapsed state,

[451 Feb. 11, 1975 is a substantially rectilinear box having a height H,a width W, and a length L. The sidewalls of the container are formed bythe hinged combination of six rectangular, rigid sidewall panels. Thefloor structure of the container is made up of two trapezoidal panels,each having a long base edge of length L and a short base edge of length(L W), and four right-triangular panels having two edges of equal lengthW/2. A twoway mechanical drive is connected between the opposing pairsof end-wall panels to collapse or erect the container in a singleoperation. The two larger sidewall panels are unaffected during thecollapsing and erecting operation, allowing access doors to be placedtherein as desired. Wheels mounted at the lower four corners of thecontainer are operable when the container is either collapsed orerected. A center bar positioned under the floor panels provides a guidefor carriages which are screw-driven from a rotary power source, andfurther acts as a floor support joist. The center bar supports the floorpanels in a co-planar, toggle-locked position. Ramp flanges extendingdownwardly from the floor panels engage with a moving carriage to breakthe toggle-lock by lifting the floor at the beginning of the collapsingoperation.

14 Claims, 14 Drawing Figures PATENTEU F551 1 5 SHEET 1 [IF 5 i luvPATENTED F551 1 1975 3.865259 SHEET 3 [IF 5 FIELD OF THE INVENTION Thisinvention relates to collapsible containers.

BACKGROUND OF THE INVENTION Collapsible containers may be used toadvantage in warehousing, shipping, and other material-handlingoperations. When such a container is not in use, it may be collapsed tooccupy less storage space. Shipping con tainers, which must be returnedempty to their original point of shipment, may be more efficientlyloaded into transportation vehicles when collapsed.

Many collapsible containers previously designed for such purposes havebeen difficult to use in that they have required the insertion andremoval of pins or the manual actuation of levers and latches-when thecontainer is being collapsed or erected.

It is accordingly a principle object of the present invention to providea container which may be more easily collapsed and erected.

It is a further object of the present invention to provide a collapsiblecontainer which is, at the same time, sturdy, durable, low in cost,rigid, lightweight, compact and easily moved from place to place.

SUMMARY OF THE INVENTION The present invention takes the form of acollapsible container in which the sidewalls are constructed of twomain, noncollapsing side panels and two hinged pairs of rectangular endpanels. The container includes a twoway drive mechanism which applies acontracting force drawing the inner vertical edges of the two opposingend panels inwardly to collapse the container, and applies an expansionforce to the same points to erect the container.

The floor of the container is advantageously constructed of twosymmetrical folding panel arrangements, each comprising a trapezoidalpanel flanked at each end by a right-triangular panel to form one-halfof the rectangular container floor. A longitudinal support barpositioned underneath the floor acts both as a floor joist and as aguide for pivot point carriages attached to the end panels. The drivemeans alternatively applies an expanding (erecting) or a contracting(collapsing) force to these carriages, causing them to movesynchronously within the support guide bar.

Wheels positioned at the lower four corners of the container may be usedto facilitate the movement of the container in either the collapsed orerected position. The panels themselves are preferably constructed ofextruded aluminum sections which-are at the same time lightweight,rigid, and durable.

The powered drive means for collapsing and erecting the containerpreferably comprises a feed screw driven from a rotary power source.Opposing threads in the feed screw engage with threads in the twocarriages.

The floor panels are preferably allowed to reach a fully flat position,resting upon the support guide bar in a toggle-locked" state. At thebeginning of the collapsing operation, means incorporated in the drivemechanism apply a lifting force to the floor to break the toggle-lockcondition.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects, features andadvantages of the present invention may be more clearly understoodthrough a consideration of the following detailed description which ispresented in conjunction with the attached drawings in which:

FIG. 1 is a perspective view of a collapsible container embodying theprincples of the present invention, the container being shown in itserected (uncollapsed) state, ready for use;

FIG. 2 is a second perspective view of the container. this time showingthe half-panel loading door in one sidewall of the container in the openposition;

FIG. 3 is a third perspective view of the container, showing thefull-panel unloading door in the other sidewall in its open position;

FIGS. 4, 5 and 6 are perspective views respectively showing thecontainer in the erected, partially collapsed, and fully collapsedstates, FIG. 5 showing the container with part of the outer walls brokenaway to better illustrate the manner in which the six hinged panelsmaking up the container floor fold upwardly into the container as itcollapses;

FIG. 7 is a top view of the container in its erected state showing theshape of each of the six hinged floor panels;

FIG. 8 is a side elevational view of the container shown with thehalf-panel loading door in its closed position;

FIG. 9 is a detail cross-section, taken along the line 9-9 of FIG. 7,showing the details of the two-way collapsing-erecting drive mechanism;

FIG. 10 is a top plan view of the drive mechanism as seen from the line10-10 of FIG. 9;

FIG. 11 is a detailed partial elevation showning the tow-pin mountattached to one end of center guide bar;

FIG. 12 is a detail cross-section taken along the line 12-12 of FIG. 9showing the cross-sectional shape of the channels which form the centerguide bar and the cross-section of one of the internally mountedpivot-pin carriages;

FIG. 13 is a detail cross-section taken along the line 13-13 of FIG. 9showing the ramp flanges which extend downwardly from adjacent floorpanels, the flanges engaging with the drive mechanism to break thetogglelocked floor panels at the beginning of the collapsing operation;and

FIG. 14 is a detail cross-section taken along the line 14-14 of FIG. 11showing the configuration ofthe mating aluminum panel extrusions used toform the sidewalls of the container.

DETAILED DESCRIPTION The preferred embodiment of the present invention,as shown in FIG. 1, is a collapsible container which, when fully erected(or uncollapsed) forms a rectilinear box made up of two major sidewalls(indicated generally at 21 and 22), two endwalls (one comprising the twofolding half-wall sections 24 and 25, and the other ably an aluminumextrusion to which the sheet material (e.g., sheet 34) and horizontal,reinforcing channels (e.g., channel 35) in the major sidewalls 21 and 22are removably attached to form access doors or, alternatively, arerigidly joined as, for example, by welding. Each of the foldinghalf-walls 24, 25, 27, 28 is hinged to one of the four corner posts,either by means of standard hinges or by hinges formed by extrudingmating hinge sections asan integral part of half-wall and corner postedges.

As shown in FIG. 2 of the drawings, the wheeled container is equippedwith a retractable tow-pin mechanism, indicated generally at 37, whichmay be moved downwardly to engage with a towing chain recessed below thesurface level of the floor (as indicated at 39 in FIG. 2). To facilitatetowing the container in a curved path, the two front wheels (the wheelsnearest the towpin mechanism 37) are preferably pivotally mounted on thecontainer.

Because the two major sidewalls (21 and 22 in FIG. 1) do not fold as thecontainer is collapsed, access doors may be placed in these sidewalls asshown in FIGS. 2 and 3. The upper half of one sidewall may be fittedwith a downwardly folding door panel which, when opened (as seen in FIG.2), provides convenient access to the container as it is loaded. Forrapid unloading of the container, the other sidewall may be fitted withan outwardly opening full-panel door, hinged at the top as shown in FIG.3 (and including a springloaded counterbalance, if desired). In bothcases, the door panels may be provided with spring-loaded locking-pinmechanisms (e.g., the mechanism indicated generally at 41 in FIG. 3)which may be released by pulling a draw-cord (e.g., draw-cord 42 in FIG.3). The panels may be again secured in place, by first pulling and thenreleasing the draw-cord, so that the locking pins are re-inserted intoreceiving sockets bored in the corner posts.

As shown in FIGS. 4, 5, and 6 of the drawings, the container may becollapsed or erected in a single, simple, continuous operation. Thedrive mechanism for accomplishing this (to be described in detail later)is positioned inside a hollow center bar formed by two channels(indicated generally at 48 in FIG. which is terminated, at one end, witha socket 49 (indicated in FIG. 4) adapted to receive the powered driveshaft of a reversible motor (which may conveniently take the form of aconventional hand-held electrical power drill unit). This drivemechanism cooperates with the configuration of hinged panels making upthe containers sidewalls and floor to reduce the process of collapsingor erecting the container to a single step which does not require theadditional manual actuation of levers, latches or pins.

The collapsible floor of the container is made up of six planar panelswhose shape is clearly seen in the top view of the container, FIG. 7.The floor is divided into two, adjacent, independently operating halves,the first of which comprises two right-triangular panels 51 and 53flanking a trapezoidal panel 55. The hypotenuse edge of each triangularpanel is hinged to one of the non-parallel edges of the trapezoidalpanel. The second half of the floor comprises two right triangularpanels 57 and 58 similarly hinged to a trapezoidal panel 59.

and 58) is approximately W/2, and the two trapezoidal panels (55 and 59)have a base length substantially equal to L, the length of the shorteredge parallel to the base is substantially equal to (L W), and the baseand shorter edges of the trapezoidal panels are spaced apart by thelength W/2.

The floor panels may be joined to each other, and to the base of thesidewalls by means of conventional double-leaf hinges, or by bendingalternate, dove-tailing flanges in adjacent panels around a single boltto form an integral, continuous hinge along the entire length of eachhinged panel joint. Alternatively, the edges of the floor panels andsidewall frame members may be economically extruded (in known ways) toform a continuous, interlocking, integral hinge without requiringadditional parts.

The drive mechanism employed for erecting and collapsing the containeris shown in FIG. 9, a cross-section taken along the line-9-9 of FIG. 7.As seen at the far left in FIG. 9, the tow-pin mechanism indicatedgenerally at 37 comprises a casting 61 having a circular opening at itstop whichreceives a sleeve 62 through which a tow-pin 63 is journaled. Ahorizontal rod 65 is welded to the top of the tow-pin 63 to form aT-handle to facilitate manually extending and retracting the towpin. Aspring loaded ball 66 engages with an arcuate groove in the periphery ofthe tow-pin 63 as shown at 68 to hold the tow-pin in its open, retractedposition.

In inwardly directed extension (indicated generally at 71) forms a partof the casting 61 and is shaped to con form with the interior walls of acenter bar indicated generally at 73, the center bar 73 being composedof two opposing channel structures 75 and 77 having a cross-sectionalshape clearly seen in FIGS. 12 and 13 of the drawings. A pivot bearingindicated generally at 74 is fitted into the interior of extension 71and receives one end of a threaded shaft indicated generally at 76. Theother end of the threaded shaft 76 is inserted If the interiordimensions of the opened container are length L, height H, and width W,the equal-length into a similar pivot bearing 78 which, like theextension 71 on casting 61, conforms to the interior walls of the twochannels and 77 (seen in FIGS. 12 and 13). The internal rotating sectionof pivot bearing'78 is rigidly joined to the threaded rod 75 and has theaxially aligned, square-shaped socket opening 49 machined therein toreceive a drive shaft having a square crosssection extending from theend of the reversible motor 50 (as previously depicted generally in FIG.4).

The drive shaft 76 is threadably engages with carriage blocks indicatedat 81 and 82 in FIG. 9. As the shaft 76 rotates, carriage blocks 81 and82 move axially in opposing directions due to the opposing threaddirections at the two ends of the shaft 76.

I The carriage block 81 is coupled to a sliding block 85 by means ofatension/compression spring 87. The sliding block 85 is not threaded anddoes not engage with the drive shaft 76. Similarly, the carriage block82 is coupled to a sliding block 88 by means of a tension/- compressionspring 89.

The sliding block 85 is fastened to an end-wall pulling yoke 91 by meansof the bolt 92 as seen in FIGS. 9, l0 and 12. The pulling yoke 91 is inturn fastened to the lower horizontal frame members 95 and 96 (of thesidewalls 27 and 28 as seen in FIG. 1). The outer corners of the framemembers 95 and 96 adjacent the casting 61 are rounded with a center ofcurvature at the axis of pivot pins 93 and 94. Similarly, a pulling yoke101 is affixed to the underside of the sliding block 88 by a bolt 103and to the lower, horizontal frame members 104 and 105 (of the end-walls24 and 25, respectively, as seen in FIG. 1) by means of pivot pins 107and 109. v

The drive mechanism as depicted in FIG. 9 of the drawings is shown withthe container in its fully erected (uncollapsed) state. To collapse thecontainer, the drive shaft 76 is rotated under power such that thecarriage blocks 81 and 82 move toward one another. Before this motionbegins, springs 87 and 88 are in compression (having been left in acompressed state at the conclusion of the erection operation).

At this point, it should further be noted that the panels 51, 53 and 55which make up that half of the floor visible in FIG. 9 are in analigned, flat position, each resting upon the upper surface of thecenter bar channel 77 as seen in FIG. 12. Being fully flat, the floor isin a toggle-locked condition and the application of a force tending todraw the yokes 91 and 101 together, by itself, would be ineffective tounlock the floor so that the collapsing operation can begin. Althoughthis toggle-locked condition could be avoided by preventing the floorfrom reaching a completely flat position, a flat container floor isoften desirable, and the togglelocked floor provides structural rigidityapproximating that which would be provided by a single panel(nonfolding) floor. For this reason, in the preferred embodiment heredescribed, the floor is allowed to assume a fully flat, toggle-lockedposition and means are employed for lifting the floor panels slightly atthe beginning of the collapsing operation so that the application of apulling tension, drawing the floor and end-panels together, may completethe collapsing operation.

The mechanism for initially lifting the floor comprises an inwardlydirected operating flange member 111 which is fastened to the top ofcarriage 81 and which engages with inclined ramps formed by downwardlyextending flanges 113 and 115 which, as more clearly seen in FIG. 13 ofthe drawings, are attached to the underside of the trapezoidal floorpanels 55 and 59.

Thus, as seen in FIG. 9, as the carriage block 81 is moved to the leftby the rotation of the drive shaft 76, the sliding block 85 initiallydoes not move, spring 87 is decompressed, and the sliding flange 111engages with the inclined ramps formed by downwardly extending flanges(e.g., flange 113) to lift the floor panels out of their toggle-lockedposition. As the carriage block 81 continues its travel, the tensionapplied to spring 87 draws the sliding block 85 to the right, drawingthe yoke 91 with it, and causing the end-walls to pivot inwardly aboutthe pivot pins 93 and 94. The similar motion of carriage block 82 andthe sliding block 88 and yoke 101 causes the walls at the other end topivot inwardly about the pins 107 and 109.

When the container is fully collapsed (as indicated in FIG. 6) carriage81 continues its travel a short distance, increasing the tension onspring 87. Spring 87 thus eliminates an undesirable end-of-travel joltand the resulting spring tension secures the container in its closedposition. In a similar fashion, when the container is erected, thecompression of spring 87 after the container is fully opened eliminatesthe end-oftravel jolt and leaves the container in a spring-loaded openposition.

The springs 87 and 89 and their associated structures also provide shockabsorption between the body of the container and the tow pin 63. As bestseen in FIG. 9,

the tow pin casting 61, the floor-supporting guide channels and 77, thedrive shaft 76 and the carriages 81 and 82 together comprise a slidingstructure which is slidably movable with respect to the remainder of thecontainer. Thus, as the tow pin 63 initially engages with the moving towchain which will propel the container, this sliding structure is allowedto move (to the left, as seen in FIG. 9) with respect to the remainderof the container, further compressing spring 87 as spring 89 expands.The sliding friction between the floor and the support channels 75 and77 advantageously provides frictional damping to suppress undesirablemechanical oscillations following the initial tow pin impact.

The wall panels of the container may be advantageously and economicallyconstructed from extruded panel sections which lock together, in knownways, to form a reinforced, non-welded wall construction. FIG. 14, across-section taken along the lines l4-l4 of FIG. 1 1, illustrates atypical snap-lock wall construction suitable for fabricating a containerwherein two mating extrusions lock together to form an integral wall andreinforcing channel.

It is to be understood that the specific collapsible containerconstruction which has been described in detail is merely illustrativeof one application of the principles of the present invention. Numerousmodifications may be made to the structure as described withoutdeparting from the true spirit and scope of the invention.

What is claimed is:

1. A collapsible container comprising, in combination,

two opposing, parallel, non-folding sidewalls,

two opposing, folding end-walls, each comprising a pair of adjacentpanels joined by a vertically extending inwardly pivotable, centralboundary,

hinge means for joining the outer vertical edges of each of said foldingend-walls to the vertical edge of said non-folding sidewalls,

a floor structure adapted to be folded upwardly between said sidewallswhen said container is collapsed, and

a two'way drive mechanism for urging the central boundaries of saidopposing end-walls toward one another to collapse said container, andfor applying a reverse force urging said central boundaries away fromone another to erect said container.

2. A collapsible container as set forth in claim 1 wherein said floorstructure comprises two folding rectangular floor sections, each sectionbeing formed by the hinged combination of a trapezoidal panel and tworight-triangular panels.

3. A collapsible container as set forth in claim 1 including a hingedaccess door which forms part of one of said non folding sidewalls.

4. A collapsible container as set forth in claim 1 wherein said two-waydrive mechanism includes two threaded carriage blocks which respectivelyengage with spaced-apart sections of a rotary drive shaft, said shaftsections having opposing threads to cause said carriage blocks to movein opposite directions when said drive shaft is rotated, meansconnecting each of said carriage blocks to one of said opposingend-walls, and means for rotating said drive shaft in a first directionto erect said container and for rotating said shaft in the oppositedirection to collapse said container.

5. A collapsible container comprising, in combination,

two opposing, non-folding, major sidewall panels two folding end-wallseach comprising a pair of smaller, side-by-side panels, said smallerpanels being hinged at their outer vertical edges to the edges of saidmajor sidewall panels,

linking means pivotally connecting each pair of smaller panels at theiradjacent, inner vertical edges, and

an upwardly folding floor comprising two independent rectangular floorhalves, each comprising the combination of a trapezoidal panel hinged atits non-parallel edges to two flanking righttriangular panels, wherebythe application of force between said linking means forcing saidend-walls apart is effective to erect said container, and theapplication of an opposite force between said linking means pulling sideend-walls together is effective to collapse said container.

6, A collapsible container as set forth in claim 5, including atransverse joist positioned beneath and aligned with the boundarybetween said floor halves, said joist supporting the panels making upsaid floor in a substantially co-planar, toggle-locked configurationwhen said container is erected, and means for applying a lifting forceto said floor before said end-walls are forced together in order tobreak said toggle-locked configuration.

7. A collapsible container as set forth in claim 6 including a two-waydrive mechanism comprising first and second carriages mounted forsliding motion on said joist, a rotary drive screw threadably engagingsaid carriages in opposing thread directions such that rotation of saiddrive screw causes said carriages to advance in different directions,and means coupling each of said carriages to one of said linking means.

8. A collapsible container as set forth in claim 6 V wherein said meansfor applying a lifting force to said floor includes at least onedownwardly extending flange attached to the underside of said floor andforming an inclined ramp positioned to engage with one of saidcarriages.

9. A collapsible rectilinear container comprising, in combination,

two opposing, non-folding, rectangular sidewalls each having a height Hand a length L, first and second opposing, folding end-walls eachcomprising a'pair of vertical panels having a height substantially equalto H and length less than L/2, two folding, rectangular, half-floorsections each comprising a trapezoidal panel, the non-parallel edges ofwhich are each hinged to the hypotenuse 8 edge 'of a right-triangularpanel, each of said trapezoidal panels having its longest edge hinged tothe bottom edge of one of said sidewalls,

first and second linking means respectively connected to said first andsecond end-walls, each of said linking means being pivotally attached toboth of said pair of vertical panels adjacent their boundary, and

two-way drive means coupling said first and second linking means toforce said vertical panels outwardly into a substantially co-planarrelationship to erect said container, and for drawing said verticalpanels into facing, substantially parallel planes to collapse saidcontainer.

10. A collapsible container as set forth in claim wherein said drivemeans comprises, in combination,

a transverse guide bar positioned beneath the boundary between saidhalf-floor sections when said container is erected to support saidhalf-floor sections in a flat, coplanar relationship,

first and second carriage blocks mounted for transverse sliding motionwithin said guide bar,

a drive screw having first and second threaded segments of opposingthread directions engaging with said first and second carriage blocksrespectively,

means coupling said first and second carriage blocks to said first andsecond linking means respectively,

and

a reversible motor unit separate from said container adapted to engagewith and rotate said drive screw to erect and collapse said container.

11. A collapsible container as set forth in claim 10 including meansresponsive to the rotary motion of said drive screw at the beginning ofan erection operation for applying a lifting force to partially foldsaid halffloor sections upwardly.

12. A collapsible container as set forth in claim 11 wherein said meanscoupling said carriage blocks and said linking means includes springmeans for permitting said carriage blocks to move while said linkingmeans remain stationary.

13. A collapsible container as set forth in claim 12 wherein said meansfor applying a lifting force comprises means for translating thetransverse motion of at least one of said carriage blocks into theupward motion of said floor structures.

14. A'collapsible container as set forth in claim 12 including meanscoupled to said carriage blocks adapted to engage with moving means forpropelling said container whereby said spring means act to absorb theshock of such engagement.

1. A collapsible container comprising, in combination, two opposing,parallel, non-folding sidewalls, two opposing, folding end-walls, eachcomprising a pair of adjacent panels joined by a vertically extendinginwardly pivotable, central boundary, hinge means for joining the outervertical edges of each of said folding end-walls to the vertical edge ofsaid non-folding sidewalls, a floor structure adapted to be foldedupwardly between said sidewalls when said container is collapsed, and atwo-way drive mechanism for urging the central boundaries of saidopposing end-walls toward one another to collapse said container, andfor applying a reverse force urging said central boundaries away fromone another to erect said container.
 2. A collapsible container as setforth in claim 1 wherein said floor structure comprises two foldingrectangular floor sections, each section being formed by the hingedcombination of a trapezoidal panel and two right-triangular panels.
 3. Acollapsible container as set forth in claim 1 including a hinged accessdoor which forms part of one of said non folding sidewalls.
 4. Acollapsible container as set forth in claim 1 wherein said two-way drivemechanism includes two threaded carriage blocks which respectivelyengage with spaced-apart sections of a rotary drive shaft, said shaftsections having opposing threads to cause said carriage blocks to movein opposite directions when said drive shaft is rotated, meansconnecting each of said carriage blocks to one of said opposingend-walls, and means for rotating said drive shaft in a first directionto erect said container and for rotating said shaft in the oppositedirection to collapse said container.
 5. A collapsible containercomprising, in combination, two opposing, non-folding, major sidewallpanels two folding end-walls each comprising a pair of smaller,side-by-side panels, said smaller panels being hinged at their outervertical edges to the edges of said major sidewall panels, linking meanspivotally connecting each pair of smaller panels at their adjacent,inner vertical edges, and an upwardly folding floor comprising twoindependent rectangular floor halves, each comprising the combination ofa trapezoidal panel hinged at its non-parallel edges to two flankingright-triangular panels, whereby the application of force between saidlinking means forcing said end-walls apart is effective to erect saidcontainer, and the application of an opposite force between said linkingmeans pulling side end-walls together is effective to collapse saidcontainer.
 6. A collapsible container as set forth in claim 5, includinga transverse joist positioned beneath and aligned with the boundarybetween said floor halves, said joist supporting the panels making upsaid floor in a substantially co-planar, toggle-locked configurationwhen said container is erected, and means for applying a lifting forceto said floor before said end-walls are forced together in order tobreak said toggle-locked configuration.
 7. A collapsible container asset forth in claim 6 including a two-way drive mechanism comprisingfirst and second carriages mounted for sliding motion on said joist, arotary drive screw threadably engaging said carriages in opposing threaddirections such that rotation of said drive screw causes said carriagesto advance in different directions, and means coupling each of saidcarriages to one of said linking means.
 8. A collapsible container asset forth in claim 6 wherein said means for applying a lifting force tosaid floor includes at least one downwardly extending flange attached tothe underside of said floor and forming an inclined ramp positioned toengage with one of said carriages.
 9. A cOllapsible rectilinearcontainer comprising, in combination, two opposing, non-folding,rectangular sidewalls each having a height H and a length L, first andsecond opposing, folding end-walls each comprising a pair of verticalpanels having a height substantially equal to H and length less thanL/2, two folding, rectangular, half-floor sections each comprising atrapezoidal panel, the non-parallel edges of which are each hinged tothe hypotenuse edge of a right-triangular panel, each of saidtrapezoidal panels having its longest edge hinged to the bottom edge ofone of said sidewalls, first and second linking means respectivelyconnected to said first and second end-walls, each of said linking meansbeing pivotally attached to both of said pair of vertical panelsadjacent their boundary, and two-way drive means coupling said first andsecond linking means to force said vertical panels outwardly into asubstantially co-planar relationship to erect said container, and fordrawing said vertical panels into facing, substantially parallel planesto collapse said container.
 10. A collapsible container as set forth inclaim 9 wherein said drive means comprises, in combination, a transverseguide bar positioned beneath the boundary between said half-floorsections when said container is erected to support said half-floorsections in a flat, co-planar relationship, first and second carriageblocks mounted for transverse sliding motion within said guide bar, adrive screw having first and second threaded segments of opposing threaddirections engaging with said first and second carriage blocksrespectively, means coupling said first and second carriage blocks tosaid first and second linking means respectively, and a reversible motorunit separate from said container adapted to engage with and rotate saiddrive screw to erect and collapse said container.
 11. A collapsiblecontainer as set forth in claim 10 including means responsive to therotary motion of said drive screw at the beginning of an erectionoperation for applying a lifting force to partially fold said half-floorsections upwardly.
 12. A collapsible container as set forth in claim 11wherein said means coupling said carriage blocks and said linking meansincludes spring means for permitting said carriage blocks to move whilesaid linking means remain stationary.
 13. A collapsible container as setforth in claim 12 wherein said means for applying a lifting forcecomprises means for translating the transverse motion of at least one ofsaid carriage blocks into the upward motion of said floor structures.14. A collapsible container as set forth in claim 12 including meanscoupled to said carriage blocks adapted to engage with moving means forpropelling said container whereby said spring means act to absorb theshock of such engagement.